It is integrated natively: if you make a change on the website, it is reflected in the backend in real-time and vice versa. Your website behaves like your business processes are defined in your backend (eg. if a certain customer is supposed to be associated with a certain pricelist the ecommerce site will act accordingly; if a customer purchase a product and falls below a reordering rule it triggers automatic procurement; the payments of the attendants to an event generate invoices, payments, and accounting entries; it goes on and on with warehousing, manufacturing, billing, accounting, quotations, HR, lead generation,...). It is integrated, natively, real-time, both directions, dead simple, follows your business processes, and is open-source for advanced flexibility. Nobody else in the world does this; this is why people don't realize yet how powerful it is until a few applications front-end get released.